My criminal justice systems professor, when talking about justice in ancient civilisations told us that: "Trial on a boat - evidence heard, with further exile or death as punishment". I was wondering how much validity there was to this statement and what the reasons were for this practice.
It wasn't the usual practice, by any means. Socrates wasn't tried by this method, for instance, but rather on dry land, at the Stoa of the Basileus in the Agora.
Demosthenes, Against Aristocrates, describes this boat thing as a special case.
I mean the court held in the precinct of Phreatto. In that court, men of Athens, the law orders every man stand his trial who, having gone into exile on a charge of unintentional homicide, and being still unreconciled to the persons who procured his banishment, incurs a further charge of willful murder. The author of the several rules of court did not let such a man alone, on the ground that he was unable to return to Athens, nor did he, because the man had already committed a like offence, treat the similarity of the accusation as proof positive against him; he found a way of satisfying the requirements of religion without depriving the culprit of a fair hearing and a trial. How did he manage it? He conveyed the judges who were to sit to a place to which the accused was able to repair, appointing a place within the country but on the sea-coast, known as the precinct of Phreatto. The culprit approaches the shore in a vessel, and makes his speech without landing, while the judges listen to him and give judgement on shore. If found guilty, the man suffers the penalty of willful murder as he deserves; if acquitted, he goes his way scot-free in respect of that charge, but still subject to punishment for the earlier homicide.
It's for special cases in which someone wanted to charge an Athenian already in exile. As the defendant is in exile, they can't come to a normal court without risking the imposition of the penalty of exile. The court convened at the shore and the defendant could make a defense from the boat. Sealy in a 1983 article suggested that this process might be a remnant of an early intrusion of the state into the sphere of a private system of justice, noting the condition that the defendant be found guilty of involuntary murder and overlapping competence with the Areopagus in cases of intentional murder.